So do street vendors, those serving customers who slurp the restorative brew while perched on child-size plastic stools.

“When you eat a bowl of soup in Vietnam, you experience almost everything, culinarily speaking, that the Vietnamese value,” chef Charles Phan writes in his book “Vietnamese Home Cooking” (Ten Speed Press, $35).

Those values? A stock that’s “never thickened,” a mix of textures, plus aromatics, often fresh herbs, toasted garlic and chopped green onions. And while Phan notes that Vietnamese cooks prepare both brothy meal openers and full-meal noodle soups, it is the noodle soup called pho that is the worldwide star.

And breakfast in Vietnam. Each morning, despite the sultry weather, we slurped our way through huge bowls of comforting, herb-blessed pho.

As a child in Da Lat, Phan recalls awakening each day to street vendors selling bowls of pho.

“When people walk by, when you smell the aroma from the pot, you can tell whether it’s beef or chicken,” Vu Trong Khang, a chef at Hoa Tuc restaurant in Ho Chi Minh City and instructor for its cooking classes, told us. “You know it’s beef pho when you smell cardamom, cinnamon, star anise and cloves.”

Also influencing a stock’s flavor, says Phan: “We don’t roast the bone, we blanch the bone. … And there’s none of the sweetness that comes from celery and carrot.”

Instead, it comes from roasted onion, ginger, star anise and other spices in the beef stock, he adds. In chicken, only ginger and onion perfume the stock.

There are variations, of course, by region as well as from cook to cook. Khang, for example, considers the broth in Hanoi lighter in color than that served in Ho Chi Minh City, and Phan finds cooks in the north use fewer spices and varieties of meats.

Preparing stock for pho can be a bit involved. Or at least, it might seem that way compared with other stocks you’ve made.

In Phan’s book, he writes that the stocks “are hardly the sexiest, most exciting recipes in the book, (but) they are some of the most important.”

Consider the flavor sources, from the bones to the spices. His recipe calls for blanching bones (not roasting – because, as he explains, most Vietnamese kitchens don’t have ovens) before returning them to the pot for a long, slow simmer (five hours).

He suggests making the stock one day, the soup another.

“Don’t overwater (the stock). You can always add more water to it,” Phan says. “And pay attention to the fat ratio. Without the fat, you’re not going to taste the broth.”

“You need to skim the fat,” adds Phan. “But you need to make sure that you add some back into each bowl so you don’t (lose flavor).